The purpose of the Medical Studies Database System (MSDS) is to provide a computerized system that facilitates data handling functions with a high degree of automation, that minimizes data collection errors and computer programming and provides forms-tracking, data updating with automatic audit-trail and user-friendly data retrieval. Terminal emulation capability has been added to the system to enable intracomputer communications. This capability facilitates the retrieval of a considerable quantity of data from remote computers largely under computer control. Since these procedures require little operator intervention, the number of errors has been significantly reduced and greater qunatities of data can be handled. Additional extensions and enhancements have been made to expand the data-tracking and progress-reporting functions and to expidite the implementation of additional studies on the system. Three clinical studies, the Febrile Seizure study, the Naloxone dose-escalation study and the Pilot Hypervolemic Hemodilution study of Dextran-40 are currently being managed using this system. Maintenanace and operation of the system will continue and new medical studies may be supported by the MSDS, but the development of the system has been completed.